I don't get why the idea of pre-ordering is so weird to some people. I'm going to buy the game either way, so I'm going to pre-order on Amazon. I get it delivered to my house on day one, and I can slowly pay it off over however many months. I currently only owe 28 more dollars on it. I'd much rather do that than have to ride to a store when it comes out and pay the full price all at once, or order off of Amazon after it's release, not get it on day one, and pay the full price.
I'm about a 30 minute drive to the nearest store that sells games too, so that's probably a factor in my decision.